Question

Review Conceptual Example 7 before starting this problem.
Ammonia,which has a strong smell, is diffusing through air
contained in atube of length L and cross-sectional area of
5.88 x10-4 m2. The diffusion constant for
ammoniain air is 4.2 x 10-5 m2/s. In a
certain time,3.34 x 10-8 kg of ammonia diffuses through
the air whenthe difference in ammonia concentration between the
ends of thetube is 4.68 x 10-2 kg/m3. Find
the speed atwhich ammonia diffuses through the air, that is, the
length of thetube divided by the time to travel this length.